Noncaking detergent compositions



Patented Jan. 13, 1953 UNITED STATES PATENT OFFICE NONCAKING DETERGENT COMPOSITIONS No Drawing. Application November 22, 1949, Serial No. 128,907

21 Claims.

The present invention relates to new essentially non-abrasive detergent compositions in particulate form, more particularly to powdered, granulated, beaded, or otherwise comminuted detersive materials having improved properties; and to a process for preparing the same. By the term essentially non-abrasive it is meant that the detergent composition does not contain as the major ingredient a siliceous material such as silica.

The tendency of various materials containing surface-active agents in particulate form to cake under varying conditions of temperature, pressure, and humidity is a significant problem. Dopending upon the nature of the material and the conditions to which it has been subjected, caking may convert a free flowing powder either to a lightly packed friable state, to a sluggish damp mass, or even to a brittle, rock-like condition. Accordingly, the term caking or its equivalent as used herein refers to the change of state from a mass of discrete, more or less free flowing solid particles, to an agglomerated solid mass that is not free flowing, at least in terms of particles of the initial size. The obvious adverse effects on consumer appeal due to ca'king of a product has lead to much experimentation towards the discovery of agents which tend tominim-ize the caking tendency of various comminuted type products. Various additives such as chalk, salt, saw dust, talc, etc., have been suggested as a means of reducing the caking properties of products in particulate form with varying degrees of success.

It has now been found that the dry-mixing of essentially non-abrasive detersive compositions in particulate form, preferably in the form of granules, with a synthetic hydrated magnesium silicate material, preferably in powdered form, and having an MgOzsiOz ratio of a maximum of about 1:2 is eifective to improve the properties of such detersive compositions. By the term granules or its equivalent it is intended to include the detergent compositions in any particulate form (e. g. spray-dried, drum-dried, etc.) such that a major part of the particles of the order of about 50% and preferably at least about 75% maybe generally retained upon a standard U. S. No. 100 sieve whereas the powdered form of the magnesium silicate materials generally has reference to a finer state wherein the major amount .may pass through a similar type sieve.

The tendency of detersive compositions to cake und a e a osp ri condit ons is marke ly reduced by the incorporation of these synthetic hydrated magnesium silicate compounds which are active to maintain the composition in a substantially non-caking, free-flowing, par-ticu late state. Moreover, the addition of this particular type of magnesium silicate adduct yields a number of other significantly improved properies such as improved perfume retention and stabilization, improved whiteness (provided the detergent composition of course does not possess a pure white color) and enhanced dispersing and deflocculating power of the detersive composition in aqueous and organic solvents.

The mechanisms by which these improvements are effected are not completely understood at this time. With regard to the 'anti-caking efiec-ts, it is believed that the function of this additive probably is for adherence to the sticky surfaces of the particles of the detergent product, and thereby prevent the caking of such particles to a significant degree. Accordingly, it is generally considered more desirable to use the additive in powdered form since it can be distributed over a greater surface area of the granular detergent particles. With regard to whiteness improvement, it appears that the magnesium silicate particles become so completely distributed upon the surfaces of the treated detersive products'that the latter will assume the desirable white color of the magnesium silicate compounds. It is considered that such behavior is quite unexpected since if titanium dioxide, for example, is added to the .surface active materials in equivalent amounts neither the color nor the anti-caking properties appear to be improved to any significant degree.

The essentially non-abrasive detergent compositions in particulate form comprised by the invention contain as the essential surface active ingredient at least an organic anionic, cationic, or non-ionicdetersive compound. Where these detersive compounds are liquids under normal .con- .ditions, such as the non-ionic agents generally, they are prepared in particulate solid form after adsorption upon diatomaceous earth or similar agents in procedures well known in the art.

As examples of suitable anionic detersive compounds contemplated within the ambit of the invention are the soaps and the sulfated and .sulfonated synthetic detergents, especially those anionic detergents having about 8 to about 26 and preferably about 12 to about 22 carbon atoms to the molecule. The soaps are generally the water soluble salts of higher fatty acids or rosin acids and are usually derived from fats, oils, and waxes of animal, vegetable, or marine origin, e. g. tallow, coconut oil, tall oil, etc.; though of course, these carboxy acids may also be prepared synthetically such as by oxidation of suitable hydrocarbons.

The sulfated and sulfonated detersive compounds are also well known in the art and may be prepared from suitable organic materials which are applicable to sulfonation (true sulfonation and/or sulfation) including fatty oils, unsaturated fatty acids, mineral oils, partial fatty acid esters of alcoholic compounds, aromatic and alkylated aromatic compounds, alcohols, olefins, etc. Of the vast variety of sulfates and sulfonates suitable as active ingredients in detergent compositions, it is preferred to use the aliphatic sulfates and sulfonates of about 8 to 22 carbon atoms and the alkyl aromatic sulfonates.

The alkyl aromatic sulfonate detergents re-- ferred to may be mononuclear or polynuclear in structure. More particularly, the aromatic nucleus may be derived from benzene, toluene, xylene, phenol, cresols, phenol esters, naphthalene, derivatives of phenanthrene nuclei, etc. It has also been found that the alkyl group may vary similarly. Thus, for example, the alkyl group may be straight or branch chained and may consist of such radicals as dodecyl, hexyl, octyl, nonyl, decyl, keryl, mixed alkyls derived from fatty materials, cracked parafiin wax olefins, and polymers of lower mono olefins, etc. While the number of sulfonic acid groups present on the nucleus may vary, it is usual to have only one such group present in order to preserve as much as possible a balance between hydrophilic and hydrophobic portions of the molecule.

More specific examples of suitable alkyl aromatic sulfonate detergents are the propylated naphthalene sulfonates, the mixed butyl naphthalene sulfonates, tetrahydronaphthalene sulfonates, the various butylated diphenyl sulfonates and phenylphenol sulfonates. It is preferred, however, to use the higher alkyl aromatic sulfonates rather than the lower alkyl substituted detergents. Typical examples of this preferred class are the sulfonated and alkylated benzene type compounds wherein the alkyl group is at least 8 and preferably about 10 to about 16 carbon atoms. The benzene ring may possess other substituents including lower alkyl and hydroxy groups.

The invention is also particularly applicable to the surface-active sulfated or sulfonated aliphatic compounds, preferably having about 8-22 carbon atoms. Within the scope of such definition are the sulphuric acid esters of polyhydric alcohols incompletely esterified with higher fatty acids, e. g. coconut oil monoglyceride monosulphate, tallow diglyceride monosulfate; the long chain pure or mixed alkyl sulfates, e. g. lauryl sulfate, cetyl sulfate; the hydroxy sulfonated higher fatty acid esters, e. g. higher fatty acid esters of low molecular weight alkylol sulphonic acids, e. g. oleic acid ester of isethionic acid; the fatty acid ethanolamide sulfates; the fatty acid amides of amino alkyl sulfonic acids, e. g. lauric amide of taurine, and the like. More particularly, it is preferred to use the sulfated aliphatic compounds containing at least about 8 carbon atoms, especially those having 12 to about 22 carbon atoms to the molecule.

As suitable cationic detergents there may be noted the long chain alkyl quaternary ammonium compounds, e. g. cetyl quaternary ammonium salts. Within this group are included those salts wherein the nitrogen atom may be part of an open chain or hetrocyclic structure, such as cetyl tri-methyl ammonium chloride and cetyl pyridinium chloride. Another equivalent cationic agent is the diethylene amino ethyl oleyl amide product.

The non-ionic agents are also well known in the art including the polyoxyethylene ethers of alkyl aromatic hydroxy bodies (e. g. the alkylated polyoxyethylene phenols) and the polyoxyethylene ethers of long chain aliphaticalcohols.

The anionic and cationic surface active agents are commonly used in the form of their water soluble salts. For the synthetic anionic compounds, the alkali metal (e. g. sodium, potassium) and ammonium salts are preferred, though other salts such as amine, alkylolamine, alkaline earth metals (e. g. calcium, magnesium) salts may be used if desired. For the cationic agents the chloride, sulfate, acetate, and like salts may be employed satisfactorily.

The concentration of these active ingredients and mixtures thereof in the detergent compositions of the present invention vary widely according to the contemplated field of application. Thus, with regard to household soaps in particulate form, the composition may consist of practically pure soap with little if any builder whereas other types of soap powders may contain a substantial quantity of builders such as soda ash, phosphates, borax, etc., together with soap. The synthetic detergents designed for household and industrial cleaning generally contain at least about 10% and preferably about 20% of active ingredient by weight of total solids. Compositions with very high concentrations of synthetic active ingredient of the order of up to about are prepared for specialized uses generally. With built compositions however, it is preferred to use an active ingredient content of about 10 to about 50% concentration. The remainder of the composition generally comprises inorganic salts such as sodium sulfate, sodium chloride, phosphates, carbonates, etc.

As previously indicated, the essential additive is a synthetic hydrated magnesium silicate material having an MgOzSiOz ratio of at least about 1:2. The amount of chemically combined water may be varied according to the method of manufacture. It is preferred to use a synthetic hydrated magnesium tri-silicate, preferably havinga magnesia to silica ratio of about 1:2 to about 1:3 with varying amounts of water of hydration. This material should be used preferably in the powdered state whereby approximately a major amount of the particles may pass through a mesh, and even a 200 mesh screen. A synthetic magnesium silicate material which has given particularly satisfactory results has the approximate formula: MgO-2.5SiOz-Hz0 and the following characteristics: a bulk density of about 8 to about 12 pounds per cubic foot, moisture content of about 6 to about 12%, soluble chlorides as calcium chlorides in up to about 3%, and a pH in a 10% water suspension of about 7.5 to about 8.5. This material is most effective when used in a finely powdered form, e. g. about 99% through a 200 and even a 325 mesh screen, though satisfactory results are obtained when employed in a less fine state, e. g. about 80-95% through a 100 mesh and about 60-85% through a 200 mesh screen.

These synthetic hydrated magnesium silicates may be made in any convenient manner. One

suitable procedure for the formation of the hy-.- 'drated magnesium silicate broadly is the reaction of a hot solution of a magnesium salt of a strong acid *(e. g. magnesium chloride) upona calcium silicate for a time sufficient to effect a substantial conversion of the calcium silicate to the magnesium silicate. This procedure is more specifically described in U. S. Patent No. 2,163,525, to Lyle Caldwell.

According to the circumstances of manufacturing, the hydrated magnesium silicate may be chemically and/or physically associated with other materials, such as silicates, chlorides and the like. The presence of minor amounts of relatively inert materials is contemplated within the scope of the invention, provided the same are not significant enough to materially neutralize or adversely affect the desired improvements to be accomplished with the synthetic hydrated magnesium silicate compound.

These additives may be incorporated in the detersive composition in any suitable manner which permits the hydrated magnesium silicate to produce the desired effects. It has been found that this additive should be dry mixed with the other components of the detersive composition in order to obtain the desired results. Thus, the magnesium silicate may be added by tumbling, fiuidizing, to detergent particles While they are being conveyed from drying operations to filling machines, and .b .any other suitable means for mechanical incorporation or admixture. It is preferred to add the magnesium silicate in minor amounts efiective to produce such desired .properties of the detergent composition as improved anti-caking power, perfume retention and stabilization, enhanced defiocoulating power in aqueous and organic solvents, etc. This minor amount of additive generally varies within rather definite proportions of the order of from about /4% to about 20% by weight of the finished detergent composition, and preferably up to about The following data and examples are additionally illustrative of the present invention and it will be understood that the invention is not limited thereto.

The effect of the synthetic hydrated magnesium silicate compounds on the caking properties may be determined by exposure tests under controlled conditions. Briefly, these tests involve the subjection of a number of small standard fiber board cartons filled with a detergent composition in the form of granules to adverse conditions of temperature and humidity. The net Weights of detergent composition before and after testing are compared as an indication of the hygroscopicity of the test composition. The composition is shaken on a U. S. standard sieve No. 10 and the amount of retained matter is an indication of the degree of caking which has been caused by the adverse atmospheric conditions.

Table I sets forth the average results of such tests at 90 F. and 90% relative humidity for and 40 hours on standard spray-dried detergent compositions in granular form comprising about 35% sodium salts of higher alkyl benzene monosulfontes using 5% synthetic hydrated magnesuim tri-silicate in powdered form and several conventional anti-caking agents in like amounts for comparison. The anti-caking agent in each case is incorporated into the detergent composition by dry-mixing. The net weight of the compositions before exposure is about 230 grams.

The marked superiority of the magnesium .silicate additive for anti-caking purposes is evident from the data wherein the quantity retained on the screen by a composition containing this adduct is remarkably less than the amount of retention encountered using other additives known to be anti-caking agents. It is interesting to note moreover that the amount of water absorbed by the magnesium silicate-containing composition is of the same order as the values attained by the other compositions.

Table II indicates the effectiveness of varying amounts of dry-mixed synthetic hydrated magnesium tri-silicate in such a spray-dried alkyl aryl sulfonate composition having about 35% Amounts of magnesium silicate additive of the order of 10, 15 and 20% are also effective to markedly reduce the caking tendency in the relationship set forth. It is preferred to use not above about 10%, and preferably about /2%5.%, in detergent compositions designed for cleansing and laundering, particularly those having synthetic anionic active ingredients, since large amounts of additive, though highly satisfactory, do not yield proportionately improved results.

In each case, the color, and dispersing power in solution of these compositions of the present invention are improved to a significant degree also.

As indicated supra, these detergent compositions manifest such synergistically improved .results when the magnesium silicate has been incorporated mechanically in particulate form. The necessity for determining the proper mode of addition of the magnesium silicate is evidenced by the data in Table III setting forth the .results of similar exposure tests on astandard roll dried granular alkyl aryl sulfonate detergent composition with and without 5% synthetic 'hydrated powdered magnesium tri-silicate as an additive. The powdered magnesium silicate is incorporated by wet-mixing the same with a slurry of the detergent composition prior to rolldrying. The net weights of the compositions is about 380 grams before testing.

TABLE III 20 Hours 40 Hours Additive Increase in Retention Increase in Retention wt. on Exon No. 10 Wt. on Exon No. 10 posure screen posurc screen (in gms.) (111 gms.) (in guns.) (in gms.)

None 19. 8 75.0 35. 173. Magnesium silicate 20. 5 78. 0 34. 2 198.0

Example I A granular synthetic detergent composition (about 85-95% retained on a 100 mesh) is prepared containing about 40% water soluble higher alkyl benzene monosulfonate salts, 25% inorganic builders, 5% moisture, 1% finely powdered synthetic MgO-25SiO2-H2O, and the remainder essentially sodium sulfate with small amounts of perfume, dye, etc. Large amounts of this detergent composition are subjected to adverse climatic conditions in various sections of the United States and abroad. In all cases, the compositions containing the magnesium tri-silicate additive exhibited remarkably improved anti-caking properties and the like in comparison to the effects obtained from similar compositions without this additive.

Ezcample II An improved free-flowing detergent is prepared by mixing 95 parts of a granular commercial sodium alkyl sulfate prepared from the higher alcohols obtained by the reduction of coconut oil and containing about 35% active ingredient with 5 parts of finely powdered synthetic hydrated magnesium tri-silicate.

Example III An improved synthetic detergent composition is prepared by incorporating mechanically 5 parts by weight of synthetic hydrated powdered magnesium tri-silicate in a granular detergent composition comprising about 35% active ingredient. The active ingredient is a mixture of the sodium salts of higher alkyl aryl sulfonates and the higher alkyl sulfates in a 95:5 ratio by weight.

Similarly, detergent mixtures in which the ratio of alkyl aryl sulfonate to alkyl sulfate is 90:10 and 75:25 exhibit also satisfactory freeflowing properties.

Example IV A substantially non-caking, free-flowing particulate soap composition is prepared by incorporating mechanically about 2% powdered hydrated magnesium tri-silicate in a granular type soap composition comprising about 65'l0% sodium salts of mixed tallow and coconut oil acids, about 25% inorganic builders and minor proportions of perfume and the like.

Example V About 3 of synthetic powdered hydrated magnesium tri-silicate is incorporated in a granular commercial detergent containing as the active ingredient about 35% of the sodium salt of the sulfuric acid ester of coconut oil fatty acid monoglyceride. The resultant mixture possesses excellent free-flowing characteristics and has a desirable whiteness in color.

The term consisting essentially of as used in the definition of the ingredients present in the composition claimed is intended to exclude the presence of other materials in such amounts as to interfere substantially with the properties and characteristics possessed by the composition set forth but to permit the presence of other materials in such amounts as not substantially to affect said properties and characteristics adversely.

Although the present invention has been described with reference to particular embodiments and examples, it will be apparent to those skilled in the art that variations and modifications of this invention can be made and that equivalents can be substituted therefor without departing from the principles and true spirit of the invention.

Having described the invention, what is desired to be secured by Letters Patent is:

1. A substantially non-caking, free-flowing, non-abrasive detergent composition in particulate form consisting essentially of organic detergent in granular form admixed with a synthetic hydrated magnesium silicate material in powdered form, said silicate material having a ratio of MgO to SiOz of about 1:2 to about 1:3 in a minor amount up to about 20% by weight of said detergent composition and active to maintain the same in a substantially non-caking, free-flowing, particulate form.

2. A composition as set forth in claim 1 wherein said silicate material is a synthetic hydrated magnesium tri-silicate material having an MgO to S102 ratio of 1 to about 2.5.

3. A substantially non-caking, free-flowing non-abrasive particulate detergent composition consisting essentially of granules of an anionic organic detersive compound, and a minor proportion up to about 20% of a powdered synthetic hydrated magnesium silicate compound having a magnesium oxide to silica ratio of about 1:2 to about 1:3 and active to maintain said composition in a substantially non-caking free-flowing particulate state.

4. A detergent composition in particulate form consisting essentially of granules of an anionic organic detersive water soluble salt, and a minor proportion up to about 20% of a synthetic hydrated magnesium tri-silicate compound in relatively fine particulate form admixed therewith and effective to improve the properties of said detergent composition while in a particulate state.

5. A detergent composition consisting essentially of an anionic organic detersive water soluble salt in the form of granules and a minor proportion up to about 20% of a powdered synthetic hydrated magnesium silicate material having the approximate formula MgO-2.5SiO2-H2O admixed therewith and active to minimize the caking tendency of said detergent composition under adverse conditions.

6. A substantially non-caking, free-flowing non-abrasive particulate detergent composition consisting essentially of anionic organic detergent material in the form of granules from about 10% to about 50% by weight, and a minor proportion up to about 20% of a powdered synthetic hydrated magnesium silicate compound having a magnesium oxide to silica ratio of about 1:2 to about 1:3 and active to maintain said composition in a substantially non-caking, free-flowing particulate state.

'7. A composition as set forth in claim 6 wherein said silicate material has the approximate formula: MgO-25SiO2-H2O 8. A cleansing and laundering composition in particulate form consisting essentially of at least 9 about of anionic synthetic organic detergent granules, and a minor proportion of a powdered synthetic hydrated magnesium tri-silicate and up to about 20% by weight and active to maintain said detergent composition in a substantially non-caking, free-flowing state.

9. A detergent composition consisting essentially of a synthetic anionic organic detersive water soluble sodium salt in the form of granules and a minor proportion up to about 20% of a powdered synthetic hydrated magnesium silicate 'material having the approximate formula MgO 2.58102 H2O admixed therewith and active to minimize the caking tendency of said detergent composition under adverse conditions.

10. A substantially non-caking, free-flowing non-abrasive particulate detergent composition consisting essentially of soap granules and a minor proportion up to about 20% of a powdered synthetic hydrated magnesium silicate compound having a ratio of MgO to $102 of about 1:2 to about 1:3 and active to maintain said composition in a substantially non-caking, free-flowing particulate state.

11. A detergent composition in particulate form consisting essentially of granules of soap, and a minor proportion from about to about 10% of a powdered synthetic hydrated magnesium tri-silicate compound admixed therewith which is effective to improve the properties of said detergent composition while in a particulate state.

12. An essentially non-abrasive detergent composition in particulate form consisting essentially from about 10% to about 50% of anionic synthetic organic detergent material selected from the group consisting of sulfates and sulfonates in granular form, a minor proportion from about 0.5% to about 20% of a synthetic hydrated magnesium silicate material having an MgO to $102 ratio of about 1:2 to about 1:3 in powdered form admixed therewith.

13. A substantially non-caking, free-flowing essentially non-abrasive particulate detergent composition consisting essentially of alkyl aryl sulfonate water soluble salts in the form of granules, and a minor proportion from about to about 10% of a powdered synthetic hydrated magnesium silicate compound having an MgO to SiOz ratio of about 1:2 to about 1:3 and active to maintain said composition in a substantially non-caking, free-flowing particulate state.

14. A detergent composition in particulate form consisting essentially of granules of a higher alkyl aryl sulfonate detersive salt and a minor proportion up to about 20% of a powdered synthetic hydrated magnesium tri-silicate compound admixed therewith which is efiective to improve the properties of said detergent composition while in a particulate state.

15. A detergent composition consisting essentially of a higher alkyl mononuclear aryl sulfonate water soluble salt in the form of granules and a minor proportion from about /2% to about 10% of a powdered synthetic hydrated magnesium silicate material having the approximate formula MgO-2.5SiO2-H2O admixed therewith and active to minimize the caking tendency of said detergent composition under adverse conditions.

16. A substantially non-caking, free-flowing particulate detergent composition consisting essentially of higher alkyl mononuclear aryl sulfonate detergent material from about 10% to about 50% by weight, and a minor amount from about 0.5% to about 10% by weight of a synthetic hydrated magnesium silicate compound having the approximate formula: MgO"2.5SiO2 admixed therewith.

17. A substantially non-caking, free-flowing detergent composition in particulate form consisting essentially of granules of sulfated aliphatic detergents having about 12 to about 22 carbon atoms, and a minor proportion up to about 20% of a powdered synthetic hydrated magnesium tri-silicate compound admixed therewith and active to maintain said composition in a substantially non-caking, free-flowing particulate state.

18. A substantially non-caking, free-flowing particulate detergent composition consisting essentially of granules of a higher alkyl sulfate salt and a minor proportion up to about 20% of a powdered synthetic hydrated magnesium silicate compound admixed therewith and active to maintain said composition in a substantially non-caking free-flowing particulate state, said silicate material having an MgO to $102 ratio of about 1:2 to about 1:3.

19. A detergent composition in particulate form consisting essentially of higher alkyl sulfate detersive salts in granular form, and a minor proportion from about /2% to about 10% of a powdered synthetic hydrated magnesium tri-silicate compound admixed therewith which is effective to improve the properties of said detergent composition while in a particulate state.

20. A substantially non-caking, free-flowing particulate solid detergent composition consisting essentially of granules of water soluble salts of sulfuric acid esters of polyhydric alcohols incompletely esterified with at least a higher fatty acid, and a minor proportion up to about 20% of a powdered synthetic hydrated magnesium silicate having a magnesium oxide to silica ratio of about 1:2 to about 1:3 and active to maintain said composition in a substantially non-caking, free-flowing particulate state.

21. A detergent composition in particulate form consisting essentially of granules of a water soluble higher fatty acid monoglyceride monosulfate salt, and a minor proportion from about A% to about 10% of a powdered synthetic hydrated magnesium tri-silicate compound admixed therewith which is eifective to improve the properties of said detergent composition while in a particulate state.

HANS GEORGE KIRSCHENBAUER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,943,584 Cross Jan. 16, 1934 1,945,534 Rembert Feb. 6, 1934 1,968,628 Alton July 31, 1934 2,258,587 Goodner Oct. 14, 1941 2,296,689 Soderberg Sept. 22, 1942 2,399,655 Alton May 7, 1946 FOREIGN PATENTS Number Country Date 348,184 Great Britain May 8, 1931 

1. A SUBSTANTIALLY NON-CAKING, FREE-FLOWING NON-ABRASIVE DETERGENT COMPOSITION IN PARTICULATE FORM CONSISTING ESSENTIALLY OF ORGANIC DETERGENT IN GRANULAR FORM ADMIXED WITH A SYNTHETIC HYDRATED MAGNESIUM SILICATE MATERIAL IN POWDERED FORM, SAID SILICATE MATERIAL HAVING A RATIO OF MGO TO SIO2 OF ABOUT 1:2 TO ABOUT 1:3 IN A MINOR AMOUNT UP TO ABOUT 20% BY WEIGHT OF SAID DETERGENT COMPOSITION AND ACTIVE TO MAINTAIN THE SAME IN A SUBSTANTIALLY NON-CAKING, FREE-FLOWING, PARTICULATE FORM. 